NIL
1.2.3.4.5.6.7.8.9.10.11
12
1.2.3.4.5.6.7.8.9
12.13.14.15.16.17.18
12.13.14.15.16.17.18.19
20.21.22.23.24.25.26.27
28.29.30.31
28.29.30